Are firearms with a silencer ‘quiet’?

Donald Trump Jr. fires a SilencerCo Maxim 9 pistol during a visit to the company in Utah. SilencerCo’s Maxim 9 is a 9mm semiautomatic handgun, with a 15-round magazine, that’s permanently integrated with a silencer. (Courtesy of SilencerCo)

“You know what protects your hearing better than a silencer? Ear plugs.”— Americans for a Responsible Solution, in a tweet, March 13

“When someone gets shot by a gun with a silencer, it’s quiet. Witnesses might not hear. Police will be less likely to track down the shooter.”— Sen. Kirsten Gillibrand (D-N.Y.), in a tweet, March 14

Congress is preparing to debate the so-called Hearing Protection Act, which would streamline the purchase of suppressors for firearms. To buy a suppressor, more popularly known as a silencer, one must meet a number of requirements that result in a nine-month approval process (including submitting fingerprints and a photograph) and a $200 tax stamp. (A silencer generally costs hundreds of dollars, and can easily top $1,000.) The legislation would make buying a suppressor as easy as buying a firearm (with an instant background check), and do away with the tax stamp and federal registration.

We obviously take no position on whether this proposed law would be good or bad, but we were curious about this pair of tweets. Americans for a Responsible Solution (ARS), in its tweet, further noted that the law “would make it easier for active shooters to inflict serious harm on our communities without being detected by trained law enforcement professionals.”

What’s the impact of a suppressor on firearm noise? Does it actually make the firearm quiet or is that simply something you see in the movies?

The Facts

The Environmental Protection Agency developed the noise-reduction rating (NRR), which explains how much a product might reduce noise in decibels. The decibel scale is logarithmic, rather than linear, so a difference of a few decibels is important.

Of course, different ear protection has different ratings. We found that the range for ear plugs ranged from 22 to 33 NRR, over-the-ear muffs between 22 and 31 NRR and suppressors were also in 30 NRR range, although some may go higher.

(In all likelihood, the level of noise reduction is overestimated, especially for ear plugs because tests are done in a laboratory setting and people using them often do not achieve the proper fit. 3M advises cutting the NRR by more than half to reflect this problem, so 29 NRR would translate to 11 NRR.)

Katie Peters, a spokeswoman for ARS, supplied an article that stated: “The average suppression level, according to independent tests done on a variety of commercially available suppressors, is around 30 dB, which is around the same reduction level of typical ear protection gear often used when firing guns.”

If that’s the case, we’re not sure why the group would say that ear plugs protect hearing “better” than suppressors.” It seems the answer is that they are about the same, give or take two or three decibels. And if that’s the case, ARS is especially wrong to claim that legislation to make it easier to buy such devices “does nothing to protect hearing.”

Peters acknowledged that gun enthusiasts recommend that even with suppressors, other hearing protection is necessary. Hearing damage begins to occur at about 85 decibels, about the sound of a hairdryer.

This gets us to the other issue — whether a suppressor makes it “quiet,” as Gillibrand tweeted, and harder for law enforcement officials to detect, as she and ARS suggested.

A 30-decibel reduction in theory means an AR-15 rifle would have a noise equivalent of 132 decibels. That is considered equivalent to a gunshot or a jackhammer. A .22-caliber pistol would be 116 decibels, which is louder than a 100-watt car stereo. In all likelihood, the noise level is actually higher.

So what are opponents of the law talking about?

“We aren’t necessarily talking about being out in the middle of the woods deer hunting where it is extremely quiet. Instead, gun crimes often occur in cities and in other very noisy places,” said Marc Brumer, a Gillibrand spokesman. “The shots would be heard by law enforcement or witnesses at the gun’s typical decibel level, but they often cannot be heard when a silencer is added. There are many sounds in cities that are far louder than a gunshot masked by a silencer.”

“Relative to their normal decibel level, particularly in those urban environments where gun crime often occurs, I outlined in previous email, silencers make guns impossible to hear over many common sounds and therefore ‘quiet,’ ” Brumer said.

But gun experts say that noises are not equal. “While these items/instruments/environments may be louder or as loud as firearms, none carry with them the easily recognizable sonic pulse of a gunshot,” said Bob Owens, editor of Bearing Arms, which advocates for expanded gun rights.

Peters pointed to a 2013 article in The Washington Post that said the ShotSpotter detection system may have trouble detecting shots fired from a silencer. But ShotSpotter says that information is out of date.

“In regard to gun silencers, it is more accurate to call them suppressors, as they suppress the impulsive sound of gunfire, not wholly eliminate it,” said Ralph Clark, the chief executive of ShotSpotter. “We have successfully if not inadvertently detected confirmed suppressed gunfire within our existing deployments. Although we have not formally tested the theoretical impact to our system, we intend to do some targeted testing in the near future. We believe we will have various options ranging from increasing our sensor array density to developing software/firmware to address the detection of suppressed gunfire if it were to become a widespread issue.”

Brumer also pointed to a video in which a firearms enthusiast exclaimed how “very quiet” a .22-caliber rifle was with a silencer.

But the firearm in the video is not a high-powered weapon; it has been supplied with subsonic ammunition that is even advertised as requiring no hearing protection. (“Great for backyard plinking and introducing youth to the shooting sports.”) It would not be considered a semiautomatic weapon and in fact in the video the firearms enthusiast, Dan Abraham, says “now it won’t cycle, so you have to cycle it on your own.” That’s certainly a very different situation than a standard AR-15 round, which can only to be reduced to 132 decibels with a suppressor.

Suppressors, by diffusing the noise of a weapon, may make it more difficult to locate the source of a sound, which is why they often are used by military snipers.

The Violence Policy Center, which opposes the proposed law, can point to only a handful of examples of silencers being used in violent crimes, including a case in Milwaukee last year in which undercover FBI agents sold a silencer to a man said to be planning a mass attack. “The data indicates that use of silenced firearms in crime is a rare occurrence, and is a minor problem,” says a 2007 study cited by the Violence Policy Center. But that could also be the case because silencers are so time-consuming to obtain.

Brumer emphasized that Gillibrand was only following the lead of law enforcement officials in opposing the bill. New York bans suppressors, and that would continue even if the bill became law, but she has expressed concern about suppressors being illegally trafficked into the state.

The Pinocchio Test

We can understand the irritation of gun-control advocates about legislation with a benign-sounding name such as the Hearing Protection Act. Clearly the main impact of the measure would be to loosen restrictions on the purchase of suppressors that have been in place for decades. It would be better called the Paperwork Reduction Act, especially because the use of suppressors does not mitigate the need for hearing protection.

But that title does not give opponents the liberty to stretch the facts.

It’s debatable that ear plugs protect ears better than a suppressor — and meanwhile, no self-respecting gun owner would use an AR-15 rifle without ear protection, even if he or she had a suppressor. Certainly the two in combination would provide better ear protection than one type alone, especially because the NRR of earplugs in regular use is probably overstated. So ARS’s tweet is rather misleading.

In the meantime, although the popular name of this accessory is a silencer, foes of the law such as Gillibrand should not use misleading terms such as “quiet” to describe the sound made by a high-powered weapon with a suppressor attached. We wavered between Two and Three Pinocchios, but finally tipped to Three. There is little that’s quiet about a firearm with a silencer, unless one also thinks a jackhammer is quiet.